A pocket is known that is designed to accommodate such a biopharmaceutical product, which comprises a lower end wall, an upper end wall, and, between them, a flexible side wall that can be—in line with the pocket itself—in two extreme states—a flat-folded state, and an expanded, unfolded state—and can be deformed to switch from one of these extreme states to the other or be in any intermediate state. The walls of the pocket, made of plastic such as polyethylene or a complex that comprises polyethylene, define an inner space that, in the folded state, has a minimum and even zero or almost-zero volume, and, in the unfolded and expanded state, has a maximum volume. This space is designed to accommodate the biopharmaceutical product.
Such a pocket is designed either for simple storage of the biopharmaceutical product or for specific processing, i.e., any action on the product or relative to this product and involving contact with the product, such as mixing, aeration, filtration, and measurement, whereby this list is not exhaustive. For this purpose, such a processing means that is suitable for the desired action, such as a mixing propeller, aerator, filter, or probe is implemented, whereby this list is not exhaustive. Such a (or such) processing means is (are), at least in part, placed actually inside the pocket by being adjacent to its lower portion (on it, close to it, or in its vicinity), so as to be able to be in contact with the product.
The preceding constructive arrangements are not without risk. Actually, when the pocket is in the flat-folded state or in a slightly unfolded or nearly folded state or switches from one of these states to the other, there is a risk that the active inner portion of the processing means will interfere with the wall of the pocket, more particularly the wall of the upper end, and more or less significantly alter its integrity and its qualities by embrittling it, perforating it or tearing it. Furthermore, there is also a risk that the active inner portion of the processing means will interfere with exogenic elements that are outside of the pocket (such as supports or other devices that are next to the pocket) and be more or less significantly altered, for example deformed or moved or else wedged.
These constructive arrangements exhibit another drawback, namely not allowing complete draining of the contents of the pocket. Actually, the pocket under the action of the reduction of pressure resulting from draining flattens against the active inner portion of the processing means with a serious risk of tearing, most often compensated for by not draining the pocket completely.
The document WO 00/04131 describes a pocket with gussets having a side portion, an upper portion, and a lower portion, designed to contain one (or more) such biopharmaceutical product(s), with a volume of 50 liters and more. Such a pocket can be found either in a flat-folded state for being stored empty or in an unfolded and expanded state where it has a general pallelepipedic shape when it contains a product. According to the embodiments, such a pocket also comprises, in the upper portion, one (or several) opening(s) or connection(s) designed to allow its filling and, in the lower portion, an outlet that is designed to allow it to drain.
The document U.S. Pat. No. 5,350,080 describes a system that comprises a rigid outer container that supports a pocket that defines an inner storage chamber whose access is possible through a filling port that is located in the upper portion and a draining port that can be provided in the lower portion. When the contents of the pocket are drained, the upper filling port is forced by its own weight toward the lower portion of the pocket. In the case where the inner portion of the filling port has no tube, it can come into contact with the lower portion of the pocket, where there is the risk that it may become damaged and locked. Also, it is provided that the filling port comprises a side skirt whose height is greater than the length of the downward projection of the inner portion of the filling port, such that this inner portion is housed entirely within the skirt and its lower end is always located above the lower portion of the pocket, even when the skirt rests on the latter.
The documents US 2007/0224676 and GB 2 080 756 describe receptacles that comprise an accordion-like flexible side wall, capable of being folded or unfolded, and, on both sides of the latter, two end walls, respectively, lower and upper, whereby the latter is provided with an opening.